If you download the Ubuntu ISO and burn the image to a CD you can then boot from the CD and not install Ubuntu but run it as a live system.  It has Firefox for web browsing and many other programs already on the CD.  It does not have Flash or JAVA.

You can browse the net without fear because first your operating system is on a CD and second Ubuntu (a Linux distro) isn't subject to many virus's.

Get a flash drive and save stuff on the flash drive.  If you have a computer made in the last 4 to 5 years with USB and your printer is hooked to the computer that way there is an excellent chance that Ubuntu will recognize and install drivers for it.  I have a Canon 610 printer/scanner and Ubuntu works with both the printer and scanner.  It was no different to install than Windows.

If you have more questions post them.  I'm no expert on the subject but I'm certain others here will know the answer if I don't.